α-olefin is an industrially important raw material monomer that is produced by the oligomerization of ethylene using a metal catalyst. However, the oligomerization of ethylene usually gives et-olefin mixtures according to Schulz-Flory distribution. Therefore, the development of a catalyst system capable of selectively producing one kind of α-olefin is very important industrially.
For example, Patent Document 1 has reported that a half-metallocene titanium complex represented by formula (Cp-B(R)nAr)TiR13 activated with an activating co-catalyst component works as a catalyst for selective trimerization of ethylene.
Among these catalysts for selective ethylene trimerization, a half-metallocene titanium complex (carbon-bridged Cp-Ar complex) comprising cyclopentadiene bonded to a substituted aryl group via a carbon atom, such as [1-(1-methyl-1-(3,5-dimethylphenyl)ethyl)-3-trimethylsilylcyclopentadienyl]titanium trichloride, has been reported to work as an efficient catalytic component for ethylene trimerization under conditions of 30° C. with MAO (methylaluminoxane) as an activating co-catalyst component (see e.g., Non-Patent Document 1). On the other hand, [dimethylphenylsilylcyclopentadienyl]titanium trichloride, which is a half metallocene titanium complex (silicon-bridged Cp-Ar complex) comprising cyclopentadiene bonded to a substituted aryl group via a silicon atom, has been reported to have low catalytic activity in ethylene trimerization reaction under the same conditions as above and to also have low 1-hexene selectivity (see Non-Patent Document 1).